def calc(df):
    score = 1.0
    for i in range(365):
        if i % 7 in [0, 6]:
            score *= 0.99
        else:
            score *= 1.0 + df
    return score


def solve():
    df = 0.01
    while calc(df) < 37.78:
        df += 0.01
    print(df)


if __name__ == "__main__":
    solve()
